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Abstract

The water vapour permeances of two types of spunbonded plastic roofunderlay films are measured using different methods. Experiments with isother mal permeance cup procedures are discussed. Because of the high permeance of the tested films, the analysis of these measurements is not as simple as described in most standards. To obtain reliable results of the cup tests, the influence of the water vapour diffusion resistance of the air films is separately investigated. A non-isothermal per meance test was developed to measure the effect of surface condensation on the va pour permeance of the films. The paper describes the apparatus and discusses the re liability of the method. The properties measured by the non-isothermal test method are compared to those obtained with the isothermal method.

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References

Schulze, H. 1993. "Warum diffusionsoffene Unterspannbahnen?" ("Why Vapour Open Underlay Fims?"), Warme und Kalte Schutz im Bau , 3:1-4 (in German).

Communications with D. M. Burch, National Institute of Standards and Technology, Gaithersburg, Maryland , USA; H. Künzel , Fraunhofer Institut fur Bauphysik , Holzkirchen, Germany; T. Ojanen , VTT Building Technology , Espoo, Finland; J. Straube , Buildmg Engineering Group, University ofWaterloo, Canada. June 1996.

Ojanen, T. "Criteria for the Hygrothermal Performance of Wind Barrier Structures ," Building Physics in the Nordic Countries, 3:643-652, Copenhagen, September 13-15, 1993.

Janssens A. , H. Hens and A. Silberstein. 1995. "A Study of Parameters Influencing the Hygric Behavior of Insulated Sloped Roofs without Air Barrier," Proceedings of the Thermal Performance of the Exterior Envelopes of Buildings VI, Clearwater Beach, Florida, pp. 111-118.

Rousseau, J. 1992. "Creating Effective Air Barriers: Materials and Techniques ," Proceedings of the Thermal Performance of the Exterior Envelopes of Buildings V, Clearwater Beach, Florida , pp. 646-651.

Astm. 1989. "Standard Test Methods for Water Vapour Transmission of Materials,"ASTM E96-80.Annual Book ofASTMStandards, Section 4,Vo1.4. West Conshohoken, PA:American Society of Testing and Materials .

DIN 52 615.1973. Bestimmung der Wasserdampfdurchlässigkeit von Bau- und Dammstoffen. 6 pp., June.

Fanney, A.H. , W.C. Thomas , D.M. Burch and L.R. Mathena , Jr. 1991. "Measurements of Moisture Diffusion in Building Materials," ASHRAE Transactions , 2:99-113.

Standaert, P. 1984. "Two- and Three-Dimensional Heat Transfer: Numerical Methods, Experimental Study and Applications in Building Physics," doctoral dissertation K. U. Leuven (in Dutch), 179 pp.

Water Vapour Transfer Properties of Spunbonded Plastic Films

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